MMS 3500 swap

[ricklovin93]

has anybody done the 3500 swap into their 3100 wbody (1st gen). I was looking at the mms website and they have a kit for everything you need to swap a 3500 in, has anybody used this and how difficult was it?

[19Cutlass94]

Dont go to MMS. They are garbage. www.Wot-Tech.com and you cant swap on 3500 heads to your 3100. Youd have to go with 3400 heads then 3500 intakes.

[RobertISaar]

Dont go to MMS. They are garbage. www.Wot-Tech.com and you cant swap on 3500 heads to your 3100. Youd have to go with 3400 heads then 3500 intakes.

 

TECHNICALLY, you can...

 

the secret is that you have to significantly overbore the 3100 block to allow the 3500 heads to work and not have an overlap issue.

 

but at that point, it's already better to just start off with a 3400 or 3500 block.

[ricklovin93]

maybe i should just go all in with a 3800?

[ctracer]

if you go all in with a 3800 youll probably need a trans as the 4t60 wont be able to handle it. i personally would rather go 3800.

[ricklovin93]

sounds like to much work, how about complelty swapping a 3400 in place of the 3100?

[19Cutlass94]

3500 would be best. But it all depends on how much you wanna spend..

[Ramblin Garage]

3500 and turbo it, those are great turbo engines!

[ricklovin93]

will the 3500 bolt to the tranny, does it use the same engine mounts, what kind of changes will i have to do with wiring, can i run the engine with my 3100 pcm, do the sensors interchange? if anybody has done this swap let me know how it went?

[19Cutlass94]

Dude you gotta start searching...

 

The 3500 will bolt up, same bellhousing pattern, use your 3100 mounts. Most of the wiring is the same. Youll need a crank trigger, for best performance youll need a tune.

[RobertISaar]

assuming he's referring to his 96, it's PCM will likely not like the lack of a 24X sensor. and IIRC, the 3500 uses a different type of knock sensor(the 2 wire unit instead of the 1 wire) so that will likely need to be worked around.

[19Cutlass94]

Knock sensors are different. I dount itll run very good on the 3100 injectors as well. I thought the crank trigger converted it to a 24X?

[RobertISaar]

crank trigger makes only the 7X signal that the ICM needs to make the 3X signal sent to the PCM in almost every 87ish-05ish 60V6 application. the 24X reluctors would normally be on the damper, which IIRC, is where the 7X crank trigger goes.

 

the most foolproof option that i can think of would be to disassemble the engine, pull the crank and have the internal reluctor wheel of the 3500 removed, have a 2.8/3.1/3.4/3100/3400 one pressed on, and then run a 3100/3400 damper with the 24X reluctor in it, to give the PCM both signals it wants to see.

[ricklovin93]

the smartest thing i think will be a 3400 swap with the reasearch ive done it seems like its a pretty much drop it in and start it up swap, ill just need a newer egr, pretty sure i wouldnt need a pcm for a 3400 but ill have to look into that

[19Cutlass94]

3400 is the easiest swap. You can run it on your 3100PCM.

 

crank trigger makes only the 7X signal that the ICM needs to make the 3X signal sent to the PCM in almost every 87ish-05ish 60V6 application. the 24X reluctors would normally be on the damper, which IIRC, is where the 7X crank trigger goes.

 

the most foolproof option that i can think of would be to disassemble the engine, pull the crank and have the internal reluctor wheel of the 3500 removed, have a 2.8/3.1/3.4/3100/3400 one pressed on, and then run a 3100/3400 damper with the 24X reluctor in it, to give the PCM both signals it wants to see.

 

 

External crank trigger for LX9 3500 engines. Allows the use of LX9 in older vehicles using OBD-I, OBD-1.5 & OBD-II ECMs. Includes trigger wheel, CPS mount and includes all hardware for mounting. Mount is adjustable and marked in degrees to allow adjustment of base timing.

 

?

[RobertISaar]

you can ask Marc himself, the trigger wheel ONLY generates the 7X signal for the ICM.

 

maybe for OBD2 application the 24X signal can be tuned out via code deletion, but it in no way makes the 24X signal by itself.

[Ramblin Garage]

while you're at it you might as well just tune out the EGR and eliminate that issue..

[xtremerevolution]

if you go all in with a 3800 youll probably need a trans as the 4t60 wont be able to handle it. i personally would rather go 3800.

 

The 4T60E will be able to handle a N/A 3800 just fine, zero issues. Its the L67 (supercharged 3800) that will need a 4T65E as the 4T60E chain will stretch and break under the power.

 

while you're at it you might as well just tune out the EGR and eliminate that issue..

 

If this will be strictly just a project car, sure, but that extra fuel economy is a welcome addition to any daily driver.

[ricklovin93]

hey guys i was on the hp tuners site and in the supported vehicle lists it doesnt show any of the 1st gen w bodys, why is that? If i swap to a 3400 how can i do any tuning if my car isnt on the supported vehicle list

[WrathOfSocrus]

The external crank trigger from TCE does provide the 7x signal. The 3500 damper/crank pulley is larger in diameter than the 3100/3400. I'm not sure if you can use the trigger with the 3500 pulley because of this. It is designed to use a 3100/3400 pulley. Those pulleys have the correct 24x trigger and the 3500 has the bolt holes for the 24x sensor (I'm pretty sure the timing cover is the same casting as the other 3x00's). Just reuse or replace a 3100/3400 pulley and use the original 24x sensor. If you want to get really creative, it does appear that the ridge the 24x ring mounts to the 3100/3400 pulley also exists on the 3500 pulley. You would probably have to heat up the 24x ring to get it off without damaging it. Then deal with the issue of properly positioning the 7x sensor to work with the larger diameter pulley. More hassle than it is worth since u can just use the smaller pulley and not be overdriving your belt drive accessories.

 

On the other hand, the engine mounts are not all the same. The bolt bosses for 2 of the rear engine-to-trans mounts moved. The 4T65E uses the ones that didn't move, but the 4T60 mount needs modification. The passenger side dogbone mount will need some grinding as they lengthened 2 of the bolt bosses there. There is a casting seam on the mount which makes it easy to grind close to the line then fine tune it till it fits.

 

Most of the other items such as the coolant line, coolant sensors, EGR and such would need to be dealt with in either a 3500 or 3400 swap. You can find some of the answers on the 60 degree forums, but you will probably have to ask questions as the 3500swap sticky left me with more questions than answers. That and several hours of my life missing.

[jman093]

hey guys i was on the hp tuners site and in the supported vehicle lists it doesnt show any of the 1st gen w bodys, why is that? If i swap to a 3400 how can i do any tuning if my car isnt on the supported vehicle list

 

No, but there are Gen 2 PCM's that can be swapped. Most guys (like myself) just use a DHP Powertuner though.

[ricklovin93]

will dhp work with a 1996 l82 3100 i thought i read somewhere that the 1996 pcms are un tunable

[RobertISaar]

IIRC, DHP is the only option for the 96 V6 PCMs. i think tunercat supported them at one time, but they haven't sold their OBD2 kit since they licensed it out to JET as the JET DST.

[ricklovin93]

so what are my options without the dhp, what pcm should i use?

[RobertISaar]

BXX would know, but i think he would recommend the 98-99 MC/Lumina unit.